I already had my Bachmann class 25 loco, which I bought after driving a real one. I never managed to get it to run right as there was barely sufficient clearance for the Märklin skate, it fouled the moulding for the axles and I didn't fancy cutting the plastic and risk damaging the gear cogs as both bogies are powered (driven by one central motor) meaning that it would run fine in a straight line but slipped to a standstill on points and curves.
When a Hornby class 25 appeared on Ebay that just happened to have been renumbered to the actual one I drove, I had a little bid. As it turned out mine was the only bid and I won!
Once the loco arrived I immediately bolted on a Märklin skate, still need to sort the current return to the insulated wheels but it seems to run ok for now. I realised that the latest batch of skates that I'd bought were in fact longer than the ones I'd been using. After checking again with the Bachmann loco I realised that the skate would just about clear the axles and should allow just enough clearance underneath.
So now I have two running class 25s! The Hornby version is obviously much older but is the faster of the two. It would benefit from some ballast above the bogie with the pickup skate but seems to perform quite happily around the simple loop I've constructed temporarily in the loft. They double-head reasonably well.
This is the Hornby one...
And this is the Bachmann one that's spent most of its life stuck in the box...
Underside view of both locos, the Bachmann is on top. The pickup skates just about clear the bogies.
Having realised that the longer skates solved all my problems, I then realised that the underside of the Hornby loco was identical to the underside of my old Hornby HST, one of my first projects (makes sense really I suppose) so after another half an hour of pottering, that too has been brought back into usable condition, just need a few more mk3 coaches for it.
Three more items to add to the list of running locos, not that I need more.